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      <a id="urd"></a>
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      <a id="IndexUrd" class="indexterm"></a>
      <div class="refnamediv">
        <h2>
          <span class="refentrytitle">urd</span>
        </h2>
        <p>urd — 
      A discrete user-defined-distribution random generator that can be used as a function.
          </p>
      </div>
      <div class="refsect1">
        <a id="idp160256448"></a>
        <h2>Description</h2>
        <p>
      A discrete user-defined-distribution random generator that can be used as a function.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp160257632"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">aout = <span class="command"><strong>urd</strong></span>(ktableNum)</pre>
        <pre class="synopsis">iout = <span class="command"><strong>urd</strong></span>(itableNum)</pre>
        <pre class="synopsis">kout = <span class="command"><strong>urd</strong></span>(ktableNum)</pre>
      </div>
      <div class="refsect1">
        <a id="idp160337040"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>itableNum</em></span> -- number of table containing the random-distribution function.  Such table is generated by the user. See <a class="link" href="GEN40.html" title="GEN40">GEN40</a>, <a class="link" href="GEN41.html" title="GEN41">GEN41</a>, and <a class="link" href="GEN42.html" title="GEN42">GEN42</a>. The table length does not need to be a power of 2
    </p>
      </div>
      <div class="refsect1">
        <a id="idp160341152"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>ktableNum</em></span> -- number of table containing the random-distribution function.  Such table is generated by the user. See <a class="link" href="GEN40.html" title="GEN40">GEN40</a>, <a class="link" href="GEN41.html" title="GEN41">GEN41</a>, and <a class="link" href="GEN42.html" title="GEN42">GEN42</a>. The table length does not need to be a power of 2
    </p>
        <p>
      <span class="emphasis"><em>urd</em></span> is the same opcode as <a class="link" href="duserrnd.html" title="duserrnd"><em class="citetitle">duserrnd</em></a>, but can be used in function fashion. 
    </p>
        <p>
      For a tutorial about random distribution histograms and functions see:

      </p>
        <div class="itemizedlist">
          <ul class="itemizedlist" style="list-style-type: disc; ">
            <li class="listitem">
              <p>
            D. Lorrain. "A panoply of stochastic cannons". In C. Roads, ed. 1989. Music machine. Cambridge, Massachusetts: MIT press, pp. 351 - 379.
          </p>
            </li>
          </ul>
        </div>
        <p>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp160348992"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the urd opcode. It uses the file <a class="ulink" href="examples/urd.csd" target="_top"><em class="citetitle">urd.csd</em></a>.
            </p>
        <div class="example">
          <a id="idp160350848"></a>
          <p class="title">
            <strong>Example 960. Example of the urd opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac   <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o urd.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span>  <span class="op">=</span> 1

<span class="oblock">instr</span> 1 

ktab  <span class="op">=</span> 1			<span class="comment">;ftable 1</span>
kurd  <span class="op">=</span> <span class="opc">urd</span>(ktab) 
ktrig <span class="opc">metro</span> 5			<span class="comment">;triggers 5 times per second</span>
kres  <span class="opc">samphold</span> kurd, ktrig	<span class="comment">;sample and hold value of kurd</span>
      <span class="opc">printk2</span> kres		<span class="comment">;print it</span>
asig  <span class="opc">poscil</span> .5, 220<span class="op">+</span>kres, 2
      <span class="opc">outs</span> asig, asig
<span class="oblock">endin</span>

<span class="oblock">instr</span> 2

<span class="ohdr">seed</span> 0	<span class="comment">;every run new values</span>

ktab  <span class="op">=</span> 1 			<span class="comment">;ftable 1</span>
kurd  <span class="op">=</span> <span class="opc">urd</span>(ktab) 
ktrig <span class="opc">metro</span> 5			<span class="comment">;triggers 5 times per second</span>
kres  <span class="opc">samphold</span> kurd, ktrig	<span class="comment">;sample and hold value of kurd</span>
      <span class="opc">printk2</span> kres		<span class="comment">;print it</span>
asig  <span class="opc">poscil</span> .5, 220<span class="op">+</span>kres, 2
      <span class="opc">outs</span> asig, asig

<span class="oblock">endin</span>
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="stamnt">f</span>1 0 -20 -42  10 20 .3 100 200 .7 <span class="comment">;30% choose between 10 and 20 and 70% between 100 and 200</span>
<span class="stamnt">f</span>2 0 8192 10 1			  <span class="comment">;sine wave</span>

<span class="stamnt">i</span> 1 0 5
<span class="stamnt">i</span> 2 6 5
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />     
      Its output should include lines like these:
      </p>
        <pre class="screen">
 i1   184.61538
 i1   130.76923
 i1   169.23077
 i1    12.00000
.......

WARNING: Seeding from current time 3751086165

 i2   138.46154
 i2    12.00000
 i2   123.07692
 i2   161.53846
 i2   123.07692
 i2   153.84615
......
      </pre>
        <p>
    </p>
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      <div class="refsect1">
        <a id="idp160356080"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="cuserrnd.html" title="cuserrnd"><em class="citetitle">cuserrnd</em></a>,
      <a class="link" href="duserrnd.html" title="duserrnd"><em class="citetitle">duserrnd</em></a>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp160359120"></a>
        <h2>Credits</h2>
        <p>Author: Gabriel Maldonado</p>
        <p>New in Version 4.16</p>
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